/********************************************************************
 *                                                                  *
 * THIS FILE IS PART OF THE Ogg CONTAINER SOURCE CODE.              *
 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
 *                                                                  *
 * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2014             *
 * by the Xiph.Org Foundation http://www.xiph.org/                  *
 *                                                                  *
 ********************************************************************

  function: packing variable sized words into an octet stream
  last mod: $Id: bitwise.c 19149 2014-05-27 16:26:23Z giles $

 ********************************************************************/

 /* We're 'LSb' endian; if we write a word but read individual bits,
	then we'll read the lsb first */

#include <string.h>
#include <stdlib.h>
#include <limits.h>
#include <ogg\ogg.h>

#define BUFFER_INCREMENT 256

static const unsigned long mask[] =
{ 0x00000000,0x00000001,0x00000003,0x00000007,0x0000000f,
 0x0000001f,0x0000003f,0x0000007f,0x000000ff,0x000001ff,
 0x000003ff,0x000007ff,0x00000fff,0x00001fff,0x00003fff,
 0x00007fff,0x0000ffff,0x0001ffff,0x0003ffff,0x0007ffff,
 0x000fffff,0x001fffff,0x003fffff,0x007fffff,0x00ffffff,
 0x01ffffff,0x03ffffff,0x07ffffff,0x0fffffff,0x1fffffff,
 0x3fffffff,0x7fffffff,0xffffffff };

static const unsigned int mask8B[] =
{ 0x00,0x80,0xc0,0xe0,0xf0,0xf8,0xfc,0xfe,0xff };

void oggpack_writeinit(oggpack_buffer *b) {
	memset(b, 0, sizeof(*b));
	b->ptr = b->buffer = _ogg_malloc(BUFFER_INCREMENT);
	b->buffer[0] = '\0';
	b->storage = BUFFER_INCREMENT;
}

void oggpackB_writeinit(oggpack_buffer *b) {
	oggpack_writeinit(b);
}

int oggpack_writecheck(oggpack_buffer *b) {
	if (!b->ptr || !b->storage)return -1;
	return 0;
}

int oggpackB_writecheck(oggpack_buffer *b) {
	return oggpack_writecheck(b);
}

void oggpack_writetrunc(oggpack_buffer *b, long bits) {
	long bytes = bits >> 3;
	if (b->ptr) {
		bits -= bytes * 8;
		b->ptr = b->buffer + bytes;
		b->endbit = bits;
		b->endbyte = bytes;
		*b->ptr &= mask[bits];
	}
}

void oggpackB_writetrunc(oggpack_buffer *b, long bits) {
	long bytes = bits >> 3;
	if (b->ptr) {
		bits -= bytes * 8;
		b->ptr = b->buffer + bytes;
		b->endbit = bits;
		b->endbyte = bytes;
		*b->ptr &= mask8B[bits];
	}
}

/* Takes only up to 32 bits. */
void oggpack_write(oggpack_buffer *b, unsigned long value, int bits) {
	if (bits < 0 || bits>32) goto err;
	if (b->endbyte >= b->storage - 4) {
		void *ret;
		if (!b->ptr)return;
		if (b->storage > LONG_MAX - BUFFER_INCREMENT) goto err;
		ret = _ogg_realloc(b->buffer, b->storage + BUFFER_INCREMENT);
		if (!ret) goto err;
		b->buffer = ret;
		b->storage += BUFFER_INCREMENT;
		b->ptr = b->buffer + b->endbyte;
	}

	value &= mask[bits];
	bits += b->endbit;

	b->ptr[0] |= value << b->endbit;

	if (bits >= 8) {
		b->ptr[1] = (unsigned char)(value >> (8 - b->endbit));
		if (bits >= 16) {
			b->ptr[2] = (unsigned char)(value >> (16 - b->endbit));
			if (bits >= 24) {
				b->ptr[3] = (unsigned char)(value >> (24 - b->endbit));
				if (bits >= 32) {
					if (b->endbit)
						b->ptr[4] = (unsigned char)(value >> (32 - b->endbit));
					else
						b->ptr[4] = 0;
				}
			}
		}
	}

	b->endbyte += bits / 8;
	b->ptr += bits / 8;
	b->endbit = bits & 7;
	return;
err:
	oggpack_writeclear(b);
}

/* Takes only up to 32 bits. */
void oggpackB_write(oggpack_buffer *b, unsigned long value, int bits) {
	if (bits < 0 || bits>32) goto err;
	if (b->endbyte >= b->storage - 4) {
		void *ret;
		if (!b->ptr)return;
		if (b->storage > LONG_MAX - BUFFER_INCREMENT) goto err;
		ret = _ogg_realloc(b->buffer, b->storage + BUFFER_INCREMENT);
		if (!ret) goto err;
		b->buffer = ret;
		b->storage += BUFFER_INCREMENT;
		b->ptr = b->buffer + b->endbyte;
	}

	value = (value&mask[bits]) << (32 - bits);
	bits += b->endbit;

	b->ptr[0] |= value >> (24 + b->endbit);

	if (bits >= 8) {
		b->ptr[1] = (unsigned char)(value >> (16 + b->endbit));
		if (bits >= 16) {
			b->ptr[2] = (unsigned char)(value >> (8 + b->endbit));
			if (bits >= 24) {
				b->ptr[3] = (unsigned char)(value >> (b->endbit));
				if (bits >= 32) {
					if (b->endbit)
						b->ptr[4] = (unsigned char)(value << (8 - b->endbit));
					else
						b->ptr[4] = 0;
				}
			}
		}
	}

	b->endbyte += bits / 8;
	b->ptr += bits / 8;
	b->endbit = bits & 7;
	return;
err:
	oggpack_writeclear(b);
}

void oggpack_writealign(oggpack_buffer *b) {
	int bits = 8 - b->endbit;
	if (bits < 8)
		oggpack_write(b, 0, bits);
}

void oggpackB_writealign(oggpack_buffer *b) {
	int bits = 8 - b->endbit;
	if (bits < 8)
		oggpackB_write(b, 0, bits);
}

static void oggpack_writecopy_helper(oggpack_buffer *b,
	void *source,
	long bits,
	void(*w)(oggpack_buffer *,
		unsigned long,
		int),
	int msb) {
	unsigned char *ptr = (unsigned char *)source;

	long bytes = bits / 8;
	long pbytes = (b->endbit + bits) / 8;
	bits -= bytes * 8;

	/* expand storage up-front */
	if (b->endbyte + pbytes >= b->storage) {
		void *ret;
		if (!b->ptr) goto err;
		if (b->storage > b->endbyte + pbytes + BUFFER_INCREMENT) goto err;
		b->storage = b->endbyte + pbytes + BUFFER_INCREMENT;
		ret = _ogg_realloc(b->buffer, b->storage);
		if (!ret) goto err;
		b->buffer = ret;
		b->ptr = b->buffer + b->endbyte;
	}

	/* copy whole octets */
	if (b->endbit) {
		int i;
		/* unaligned copy.  Do it the hard way. */
		for (i = 0; i < bytes; i++)
			w(b, (unsigned long)(ptr[i]), 8);
	}
	else {
		/* aligned block copy */
		memmove(b->ptr, source, bytes);
		b->ptr += bytes;
		b->endbyte += bytes;
		*b->ptr = 0;
	}

	/* copy trailing bits */
	if (bits) {
		if (msb)
			w(b, (unsigned long)(ptr[bytes] >> (8 - bits)), bits);
		else
			w(b, (unsigned long)(ptr[bytes]), bits);
	}
	return;
err:
	oggpack_writeclear(b);
}

void oggpack_writecopy(oggpack_buffer *b, void *source, long bits) {
	oggpack_writecopy_helper(b, source, bits, oggpack_write, 0);
}

void oggpackB_writecopy(oggpack_buffer *b, void *source, long bits) {
	oggpack_writecopy_helper(b, source, bits, oggpackB_write, 1);
}

void oggpack_reset(oggpack_buffer *b) {
	if (!b->ptr)return;
	b->ptr = b->buffer;
	b->buffer[0] = 0;
	b->endbit = b->endbyte = 0;
}

void oggpackB_reset(oggpack_buffer *b) {
	oggpack_reset(b);
}

void oggpack_writeclear(oggpack_buffer *b) {
	if (b->buffer)_ogg_free(b->buffer);
	memset(b, 0, sizeof(*b));
}

void oggpackB_writeclear(oggpack_buffer *b) {
	oggpack_writeclear(b);
}

void oggpack_readinit(oggpack_buffer *b, unsigned char *buf, int bytes) {
	memset(b, 0, sizeof(*b));
	b->buffer = b->ptr = buf;
	b->storage = bytes;
}

void oggpackB_readinit(oggpack_buffer *b, unsigned char *buf, int bytes) {
	oggpack_readinit(b, buf, bytes);
}

/* Read in bits without advancing the bitptr; bits <= 32 */
long oggpack_look(oggpack_buffer *b, int bits) {
	unsigned long ret;
	unsigned long m;

	if (bits < 0 || bits>32) return -1;
	m = mask[bits];
	bits += b->endbit;

	if (b->endbyte >= b->storage - 4) {
		/* not the main path */
		if (b->endbyte > b->storage - ((bits + 7) >> 3)) return -1;
		/* special case to avoid reading b->ptr[0], which might be past the end of
			the buffer; also skips some useless accounting */
		else if (!bits)return(0L);
	}

	ret = b->ptr[0] >> b->endbit;
	if (bits > 8) {
		ret |= b->ptr[1] << (8 - b->endbit);
		if (bits > 16) {
			ret |= b->ptr[2] << (16 - b->endbit);
			if (bits > 24) {
				ret |= b->ptr[3] << (24 - b->endbit);
				if (bits > 32 && b->endbit)
					ret |= b->ptr[4] << (32 - b->endbit);
			}
		}
	}
	return(m&ret);
}

/* Read in bits without advancing the bitptr; bits <= 32 */
long oggpackB_look(oggpack_buffer *b, int bits) {
	unsigned long ret;
	int m = 32 - bits;

	if (m < 0 || m>32) return -1;
	bits += b->endbit;

	if (b->endbyte >= b->storage - 4) {
		/* not the main path */
		if (b->endbyte > b->storage - ((bits + 7) >> 3)) return -1;
		/* special case to avoid reading b->ptr[0], which might be past the end of
			the buffer; also skips some useless accounting */
		else if (!bits)return(0L);
	}

	ret = b->ptr[0] << (24 + b->endbit);
	if (bits > 8) {
		ret |= b->ptr[1] << (16 + b->endbit);
		if (bits > 16) {
			ret |= b->ptr[2] << (8 + b->endbit);
			if (bits > 24) {
				ret |= b->ptr[3] << (b->endbit);
				if (bits > 32 && b->endbit)
					ret |= b->ptr[4] >> (8 - b->endbit);
			}
		}
	}
	return ((ret & 0xffffffff) >> (m >> 1)) >> ((m + 1) >> 1);
}

long oggpack_look1(oggpack_buffer *b) {
	if (b->endbyte >= b->storage)return(-1);
	return((b->ptr[0] >> b->endbit) & 1);
}

long oggpackB_look1(oggpack_buffer *b) {
	if (b->endbyte >= b->storage)return(-1);
	return((b->ptr[0] >> (7 - b->endbit)) & 1);
}

void oggpack_adv(oggpack_buffer *b, int bits) {
	bits += b->endbit;

	if (b->endbyte > b->storage - ((bits + 7) >> 3)) goto overflow;

	b->ptr += bits / 8;
	b->endbyte += bits / 8;
	b->endbit = bits & 7;
	return;

overflow:
	b->ptr = NULL;
	b->endbyte = b->storage;
	b->endbit = 1;
}

void oggpackB_adv(oggpack_buffer *b, int bits) {
	oggpack_adv(b, bits);
}

void oggpack_adv1(oggpack_buffer *b) {
	if (++(b->endbit) > 7) {
		b->endbit = 0;
		b->ptr++;
		b->endbyte++;
	}
}

void oggpackB_adv1(oggpack_buffer *b) {
	oggpack_adv1(b);
}

/* bits <= 32 */
long oggpack_read(oggpack_buffer *b, int bits) {
	long ret;
	unsigned long m;

	if (bits < 0 || bits>32) goto err;
	m = mask[bits];
	bits += b->endbit;

	if (b->endbyte >= b->storage - 4) {
		/* not the main path */
		if (b->endbyte > b->storage - ((bits + 7) >> 3)) goto overflow;
		/* special case to avoid reading b->ptr[0], which might be past the end of
			the buffer; also skips some useless accounting */
		else if (!bits)return(0L);
	}

	ret = b->ptr[0] >> b->endbit;
	if (bits > 8) {
		ret |= b->ptr[1] << (8 - b->endbit);
		if (bits > 16) {
			ret |= b->ptr[2] << (16 - b->endbit);
			if (bits > 24) {
				ret |= b->ptr[3] << (24 - b->endbit);
				if (bits > 32 && b->endbit) {
					ret |= b->ptr[4] << (32 - b->endbit);
				}
			}
		}
	}
	ret &= m;
	b->ptr += bits / 8;
	b->endbyte += bits / 8;
	b->endbit = bits & 7;
	return ret;

overflow:
err:
	b->ptr = NULL;
	b->endbyte = b->storage;
	b->endbit = 1;
	return -1L;
}

/* bits <= 32 */
long oggpackB_read(oggpack_buffer *b, int bits) {
	long ret;
	long m = 32 - bits;

	if (m < 0 || m>32) goto err;
	bits += b->endbit;

	if (b->endbyte + 4 >= b->storage) {
		/* not the main path */
		if (b->endbyte > b->storage - ((bits + 7) >> 3)) goto overflow;
		/* special case to avoid reading b->ptr[0], which might be past the end of
			the buffer; also skips some useless accounting */
		else if (!bits)return(0L);
	}

	ret = b->ptr[0] << (24 + b->endbit);
	if (bits > 8) {
		ret |= b->ptr[1] << (16 + b->endbit);
		if (bits > 16) {
			ret |= b->ptr[2] << (8 + b->endbit);
			if (bits > 24) {
				ret |= b->ptr[3] << (b->endbit);
				if (bits > 32 && b->endbit)
					ret |= b->ptr[4] >> (8 - b->endbit);
			}
		}
	}
	ret = ((ret & 0xffffffffUL) >> (m >> 1)) >> ((m + 1) >> 1);

	b->ptr += bits / 8;
	b->endbyte += bits / 8;
	b->endbit = bits & 7;
	return ret;

overflow:
err:
	b->ptr = NULL;
	b->endbyte = b->storage;
	b->endbit = 1;
	return -1L;
}

long oggpack_read1(oggpack_buffer *b) {
	long ret;

	if (b->endbyte >= b->storage) goto overflow;
	ret = (b->ptr[0] >> b->endbit) & 1;

	b->endbit++;
	if (b->endbit > 7) {
		b->endbit = 0;
		b->ptr++;
		b->endbyte++;
	}
	return ret;

overflow:
	b->ptr = NULL;
	b->endbyte = b->storage;
	b->endbit = 1;
	return -1L;
}

long oggpackB_read1(oggpack_buffer *b) {
	long ret;

	if (b->endbyte >= b->storage) goto overflow;
	ret = (b->ptr[0] >> (7 - b->endbit)) & 1;

	b->endbit++;
	if (b->endbit > 7) {
		b->endbit = 0;
		b->ptr++;
		b->endbyte++;
	}
	return ret;

overflow:
	b->ptr = NULL;
	b->endbyte = b->storage;
	b->endbit = 1;
	return -1L;
}

long oggpack_bytes(oggpack_buffer *b) {
	return(b->endbyte + (b->endbit + 7) / 8);
}

long oggpack_bits(oggpack_buffer *b) {
	return(b->endbyte * 8 + b->endbit);
}

long oggpackB_bytes(oggpack_buffer *b) {
	return oggpack_bytes(b);
}

long oggpackB_bits(oggpack_buffer *b) {
	return oggpack_bits(b);
}

unsigned char *oggpack_get_buffer(oggpack_buffer *b) {
	return(b->buffer);
}

unsigned char *oggpackB_get_buffer(oggpack_buffer *b) {
	return oggpack_get_buffer(b);
}

/* Self test of the bitwise routines; everything else is based on
   them, so they damned well better be solid. */

#ifdef _V_SELFTEST
#include <stdio.h>

static int ilog(unsigned int v) {
	int ret = 0;
	while (v) {
		ret++;
		v >>= 1;
	}
	return(ret);
}

oggpack_buffer o;
oggpack_buffer r;

void report(char *in) {
	fprintf(stderr, "%s", in);
	exit(1);
}

void cliptest(unsigned long *b, int vals, int bits, int *comp, int compsize) {
	long bytes, i;
	unsigned char *buffer;

	oggpack_reset(&o);
	for (i = 0; i < vals; i++)
		oggpack_write(&o, b[i], bits ? bits : ilog(b[i]));
	buffer = oggpack_get_buffer(&o);
	bytes = oggpack_bytes(&o);
	if (bytes != compsize)report("wrong number of bytes!\n");
	for (i = 0; i < bytes; i++)if (buffer[i] != comp[i]) {
		for (i = 0; i < bytes; i++)fprintf(stderr, "%x %x\n", (int)buffer[i], (int)comp[i]);
		report("wrote incorrect value!\n");
	}
	oggpack_readinit(&r, buffer, bytes);
	for (i = 0; i < vals; i++) {
		int tbit = bits ? bits : ilog(b[i]);
		if (oggpack_look(&r, tbit) == -1)
			report("out of data!\n");
		if (oggpack_look(&r, tbit) != (b[i] & mask[tbit]))
			report("looked at incorrect value!\n");
		if (tbit == 1)
			if (oggpack_look1(&r) != (b[i] & mask[tbit]))
				report("looked at single bit incorrect value!\n");
		if (tbit == 1) {
			if (oggpack_read1(&r) != (b[i] & mask[tbit]))
				report("read incorrect single bit value!\n");
		}
		else {
			if (oggpack_read(&r, tbit) != (b[i] & mask[tbit]))
				report("read incorrect value!\n");
		}
	}
	if (oggpack_bytes(&r) != bytes)report("leftover bytes after read!\n");
}

void cliptestB(unsigned long *b, int vals, int bits, int *comp, int compsize) {
	long bytes, i;
	unsigned char *buffer;

	oggpackB_reset(&o);
	for (i = 0; i < vals; i++)
		oggpackB_write(&o, b[i], bits ? bits : ilog(b[i]));
	buffer = oggpackB_get_buffer(&o);
	bytes = oggpackB_bytes(&o);
	if (bytes != compsize)report("wrong number of bytes!\n");
	for (i = 0; i < bytes; i++)if (buffer[i] != comp[i]) {
		for (i = 0; i < bytes; i++)fprintf(stderr, "%x %x\n", (int)buffer[i], (int)comp[i]);
		report("wrote incorrect value!\n");
	}
	oggpackB_readinit(&r, buffer, bytes);
	for (i = 0; i < vals; i++) {
		int tbit = bits ? bits : ilog(b[i]);
		if (oggpackB_look(&r, tbit) == -1)
			report("out of data!\n");
		if (oggpackB_look(&r, tbit) != (b[i] & mask[tbit]))
			report("looked at incorrect value!\n");
		if (tbit == 1)
			if (oggpackB_look1(&r) != (b[i] & mask[tbit]))
				report("looked at single bit incorrect value!\n");
		if (tbit == 1) {
			if (oggpackB_read1(&r) != (b[i] & mask[tbit]))
				report("read incorrect single bit value!\n");
		}
		else {
			if (oggpackB_read(&r, tbit) != (b[i] & mask[tbit]))
				report("read incorrect value!\n");
		}
	}
	if (oggpackB_bytes(&r) != bytes)report("leftover bytes after read!\n");
}

void copytest(int prefill, int copy) {
	oggpack_buffer source_write;
	oggpack_buffer dest_write;
	oggpack_buffer source_read;
	oggpack_buffer dest_read;
	unsigned char *source;
	unsigned char *dest;
	long source_bytes, dest_bytes;
	int i;

	oggpack_writeinit(&source_write);
	oggpack_writeinit(&dest_write);

	for (i = 0; i < (prefill + copy + 7) / 8; i++)
		oggpack_write(&source_write, (i ^ 0x5a) & 0xff, 8);
	source = oggpack_get_buffer(&source_write);
	source_bytes = oggpack_bytes(&source_write);

	/* prefill */
	oggpack_writecopy(&dest_write, source, prefill);

	/* check buffers; verify end byte masking */
	dest = oggpack_get_buffer(&dest_write);
	dest_bytes = oggpack_bytes(&dest_write);
	if (dest_bytes != (prefill + 7) / 8) {
		fprintf(stderr, "wrong number of bytes after prefill! %ld!=%d\n", dest_bytes, (prefill + 7) / 8);
		exit(1);
	}
	oggpack_readinit(&source_read, source, source_bytes);
	oggpack_readinit(&dest_read, dest, dest_bytes);

	for (i = 0; i < prefill; i += 8) {
		int s = oggpack_read(&source_read, prefill - i < 8 ? prefill - i : 8);
		int d = oggpack_read(&dest_read, prefill - i < 8 ? prefill - i : 8);
		if (s != d) {
			fprintf(stderr, "prefill=%d mismatch! byte %d, %x!=%x\n", prefill, i / 8, s, d);
			exit(1);
		}
	}
	if (prefill < dest_bytes) {
		if (oggpack_read(&dest_read, dest_bytes - prefill) != 0) {
			fprintf(stderr, "prefill=%d mismatch! trailing bits not zero\n", prefill);
			exit(1);
		}
	}

	/* second copy */
	oggpack_writecopy(&dest_write, source, copy);

	/* check buffers; verify end byte masking */
	dest = oggpack_get_buffer(&dest_write);
	dest_bytes = oggpack_bytes(&dest_write);
	if (dest_bytes != (copy + prefill + 7) / 8) {
		fprintf(stderr, "wrong number of bytes after prefill+copy! %ld!=%d\n", dest_bytes, (copy + prefill + 7) / 8);
		exit(1);
	}
	oggpack_readinit(&source_read, source, source_bytes);
	oggpack_readinit(&dest_read, dest, dest_bytes);

	for (i = 0; i < prefill; i += 8) {
		int s = oggpack_read(&source_read, prefill - i < 8 ? prefill - i : 8);
		int d = oggpack_read(&dest_read, prefill - i < 8 ? prefill - i : 8);
		if (s != d) {
			fprintf(stderr, "prefill=%d mismatch! byte %d, %x!=%x\n", prefill, i / 8, s, d);
			exit(1);
		}
	}

	oggpack_readinit(&source_read, source, source_bytes);
	for (i = 0; i < copy; i += 8) {
		int s = oggpack_read(&source_read, copy - i < 8 ? copy - i : 8);
		int d = oggpack_read(&dest_read, copy - i < 8 ? copy - i : 8);
		if (s != d) {
			fprintf(stderr, "prefill=%d copy=%d mismatch! byte %d, %x!=%x\n", prefill, copy, i / 8, s, d);
			exit(1);
		}
	}

	if (copy + prefill < dest_bytes) {
		if (oggpack_read(&dest_read, dest_bytes - copy - prefill) != 0) {
			fprintf(stderr, "prefill=%d copy=%d mismatch! trailing bits not zero\n", prefill, copy);
			exit(1);
		}
	}

	oggpack_writeclear(&source_write);
	oggpack_writeclear(&dest_write);


}

void copytestB(int prefill, int copy) {
	oggpack_buffer source_write;
	oggpack_buffer dest_write;
	oggpack_buffer source_read;
	oggpack_buffer dest_read;
	unsigned char *source;
	unsigned char *dest;
	long source_bytes, dest_bytes;
	int i;

	oggpackB_writeinit(&source_write);
	oggpackB_writeinit(&dest_write);

	for (i = 0; i < (prefill + copy + 7) / 8; i++)
		oggpackB_write(&source_write, (i ^ 0x5a) & 0xff, 8);
	source = oggpackB_get_buffer(&source_write);
	source_bytes = oggpackB_bytes(&source_write);

	/* prefill */
	oggpackB_writecopy(&dest_write, source, prefill);

	/* check buffers; verify end byte masking */
	dest = oggpackB_get_buffer(&dest_write);
	dest_bytes = oggpackB_bytes(&dest_write);
	if (dest_bytes != (prefill + 7) / 8) {
		fprintf(stderr, "wrong number of bytes after prefill! %ld!=%d\n", dest_bytes, (prefill + 7) / 8);
		exit(1);
	}
	oggpackB_readinit(&source_read, source, source_bytes);
	oggpackB_readinit(&dest_read, dest, dest_bytes);

	for (i = 0; i < prefill; i += 8) {
		int s = oggpackB_read(&source_read, prefill - i < 8 ? prefill - i : 8);
		int d = oggpackB_read(&dest_read, prefill - i < 8 ? prefill - i : 8);
		if (s != d) {
			fprintf(stderr, "prefill=%d mismatch! byte %d, %x!=%x\n", prefill, i / 8, s, d);
			exit(1);
		}
	}
	if (prefill < dest_bytes) {
		if (oggpackB_read(&dest_read, dest_bytes - prefill) != 0) {
			fprintf(stderr, "prefill=%d mismatch! trailing bits not zero\n", prefill);
			exit(1);
		}
	}

	/* second copy */
	oggpackB_writecopy(&dest_write, source, copy);

	/* check buffers; verify end byte masking */
	dest = oggpackB_get_buffer(&dest_write);
	dest_bytes = oggpackB_bytes(&dest_write);
	if (dest_bytes != (copy + prefill + 7) / 8) {
		fprintf(stderr, "wrong number of bytes after prefill+copy! %ld!=%d\n", dest_bytes, (copy + prefill + 7) / 8);
		exit(1);
	}
	oggpackB_readinit(&source_read, source, source_bytes);
	oggpackB_readinit(&dest_read, dest, dest_bytes);

	for (i = 0; i < prefill; i += 8) {
		int s = oggpackB_read(&source_read, prefill - i < 8 ? prefill - i : 8);
		int d = oggpackB_read(&dest_read, prefill - i < 8 ? prefill - i : 8);
		if (s != d) {
			fprintf(stderr, "prefill=%d mismatch! byte %d, %x!=%x\n", prefill, i / 8, s, d);
			exit(1);
		}
	}

	oggpackB_readinit(&source_read, source, source_bytes);
	for (i = 0; i < copy; i += 8) {
		int s = oggpackB_read(&source_read, copy - i < 8 ? copy - i : 8);
		int d = oggpackB_read(&dest_read, copy - i < 8 ? copy - i : 8);
		if (s != d) {
			fprintf(stderr, "prefill=%d copy=%d mismatch! byte %d, %x!=%x\n", prefill, copy, i / 8, s, d);
			exit(1);
		}
	}

	if (copy + prefill < dest_bytes) {
		if (oggpackB_read(&dest_read, dest_bytes - copy - prefill) != 0) {
			fprintf(stderr, "prefill=%d copy=%d mismatch! trailing bits not zero\n", prefill, copy);
			exit(1);
		}
	}

	oggpackB_writeclear(&source_write);
	oggpackB_writeclear(&dest_write);

}

int main(void) {
	unsigned char *buffer;
	long bytes, i, j;
	static unsigned long testbuffer1[] =
	{ 18,12,103948,4325,543,76,432,52,3,65,4,56,32,42,34,21,1,23,32,546,456,7,
	   567,56,8,8,55,3,52,342,341,4,265,7,67,86,2199,21,7,1,5,1,4 };
	int test1size = 43;

	static unsigned long testbuffer2[] =
	{ 216531625L,1237861823,56732452,131,3212421,12325343,34547562,12313212,
	   1233432,534,5,346435231,14436467,7869299,76326614,167548585,
	   85525151,0,12321,1,349528352 };
	int test2size = 21;

	static unsigned long testbuffer3[] =
	{ 1,0,14,0,1,0,12,0,1,0,0,0,1,1,0,1,0,1,0,1,0,1,0,1,0,1,0,0,1,1,1,1,1,0,0,1,
	   0,1,30,1,1,1,0,0,1,0,0,0,12,0,11,0,1,0,0,1 };
	int test3size = 56;

	static unsigned long large[] =
	{ 2136531625L,2137861823,56732452,131,3212421,12325343,34547562,12313212,
	   1233432,534,5,2146435231,14436467,7869299,76326614,167548585,
	   85525151,0,12321,1,2146528352 };

	int onesize = 33;
	static int one[33] = { 146,25,44,151,195,15,153,176,233,131,196,65,85,172,47,40,
					  34,242,223,136,35,222,211,86,171,50,225,135,214,75,172,
					  223,4 };
	static int oneB[33] = { 150,101,131,33,203,15,204,216,105,193,156,65,84,85,222,
						 8,139,145,227,126,34,55,244,171,85,100,39,195,173,18,
						 245,251,128 };

	int twosize = 6;
	static int two[6] = { 61,255,255,251,231,29 };
	static int twoB[6] = { 247,63,255,253,249,120 };

	int threesize = 54;
	static int three[54] = { 169,2,232,252,91,132,156,36,89,13,123,176,144,32,254,
						142,224,85,59,121,144,79,124,23,67,90,90,216,79,23,83,
						58,135,196,61,55,129,183,54,101,100,170,37,127,126,10,
						100,52,4,14,18,86,77,1 };
	static int threeB[54] = { 206,128,42,153,57,8,183,251,13,89,36,30,32,144,183,
						   130,59,240,121,59,85,223,19,228,180,134,33,107,74,98,
						   233,253,196,135,63,2,110,114,50,155,90,127,37,170,104,
						   200,20,254,4,58,106,176,144,0 };

	int foursize = 38;
	static int four[38] = { 18,6,163,252,97,194,104,131,32,1,7,82,137,42,129,11,72,
					   132,60,220,112,8,196,109,64,179,86,9,137,195,208,122,169,
					   28,2,133,0,1 };
	static int fourB[38] = { 36,48,102,83,243,24,52,7,4,35,132,10,145,21,2,93,2,41,
						  1,219,184,16,33,184,54,149,170,132,18,30,29,98,229,67,
						  129,10,4,32 };

	int fivesize = 45;
	static int five[45] = { 169,2,126,139,144,172,30,4,80,72,240,59,130,218,73,62,
					   241,24,210,44,4,20,0,248,116,49,135,100,110,130,181,169,
					   84,75,159,2,1,0,132,192,8,0,0,18,22 };
	static int fiveB[45] = { 1,84,145,111,245,100,128,8,56,36,40,71,126,78,213,226,
						  124,105,12,0,133,128,0,162,233,242,67,152,77,205,77,
						  172,150,169,129,79,128,0,6,4,32,0,27,9,0 };

	int sixsize = 7;
	static int six[7] = { 17,177,170,242,169,19,148 };
	static int sixB[7] = { 136,141,85,79,149,200,41 };

	/* Test read/write together */
	/* Later we test against pregenerated bitstreams */
	oggpack_writeinit(&o);

	fprintf(stderr, "\nSmall preclipped packing (LSb): ");
	cliptest(testbuffer1, test1size, 0, one, onesize);
	fprintf(stderr, "ok.");

	fprintf(stderr, "\nNull bit call (LSb): ");
	cliptest(testbuffer3, test3size, 0, two, twosize);
	fprintf(stderr, "ok.");

	fprintf(stderr, "\nLarge preclipped packing (LSb): ");
	cliptest(testbuffer2, test2size, 0, three, threesize);
	fprintf(stderr, "ok.");

	fprintf(stderr, "\n32 bit preclipped packing (LSb): ");
	oggpack_reset(&o);
	for (i = 0; i < test2size; i++)
		oggpack_write(&o, large[i], 32);
	buffer = oggpack_get_buffer(&o);
	bytes = oggpack_bytes(&o);
	oggpack_readinit(&r, buffer, bytes);
	for (i = 0; i < test2size; i++) {
		if (oggpack_look(&r, 32) == -1)report("out of data. failed!");
		if (oggpack_look(&r, 32) != large[i]) {
			fprintf(stderr, "%ld != %ld (%lx!=%lx):", oggpack_look(&r, 32), large[i],
				oggpack_look(&r, 32), large[i]);
			report("read incorrect value!\n");
		}
		oggpack_adv(&r, 32);
	}
	if (oggpack_bytes(&r) != bytes)report("leftover bytes after read!\n");
	fprintf(stderr, "ok.");

	fprintf(stderr, "\nSmall unclipped packing (LSb): ");
	cliptest(testbuffer1, test1size, 7, four, foursize);
	fprintf(stderr, "ok.");

	fprintf(stderr, "\nLarge unclipped packing (LSb): ");
	cliptest(testbuffer2, test2size, 17, five, fivesize);
	fprintf(stderr, "ok.");

	fprintf(stderr, "\nSingle bit unclipped packing (LSb): ");
	cliptest(testbuffer3, test3size, 1, six, sixsize);
	fprintf(stderr, "ok.");

	fprintf(stderr, "\nTesting read past end (LSb): ");
	oggpack_readinit(&r, (unsigned char *)"\0\0\0\0\0\0\0\0", 8);
	for (i = 0; i < 64; i++) {
		if (oggpack_read(&r, 1) != 0) {
			fprintf(stderr, "failed; got -1 prematurely.\n");
			exit(1);
		}
	}
	if (oggpack_look(&r, 1) != -1 ||
		oggpack_read(&r, 1) != -1) {
		fprintf(stderr, "failed; read past end without -1.\n");
		exit(1);
	}
	oggpack_readinit(&r, (unsigned char *)"\0\0\0\0\0\0\0\0", 8);
	if (oggpack_read(&r, 30) != 0 || oggpack_read(&r, 16) != 0) {
		fprintf(stderr, "failed 2; got -1 prematurely.\n");
		exit(1);
	}

	if (oggpack_look(&r, 18) != 0 ||
		oggpack_look(&r, 18) != 0) {
		fprintf(stderr, "failed 3; got -1 prematurely.\n");
		exit(1);
	}
	if (oggpack_look(&r, 19) != -1 ||
		oggpack_look(&r, 19) != -1) {
		fprintf(stderr, "failed; read past end without -1.\n");
		exit(1);
	}
	if (oggpack_look(&r, 32) != -1 ||
		oggpack_look(&r, 32) != -1) {
		fprintf(stderr, "failed; read past end without -1.\n");
		exit(1);
	}
	oggpack_writeclear(&o);
	fprintf(stderr, "ok.");

	/* this is partly glassbox; we're mostly concerned about the allocation boundaries */

	fprintf(stderr, "\nTesting aligned writecopies (LSb): ");
	for (i = 0; i < 71; i++)
		for (j = 0; j < 5; j++)
			copytest(j * 8, i);
	for (i = BUFFER_INCREMENT * 8 - 71; i < BUFFER_INCREMENT * 8 + 71; i++)
		for (j = 0; j < 5; j++)
			copytest(j * 8, i);
	fprintf(stderr, "ok.      ");

	fprintf(stderr, "\nTesting unaligned writecopies (LSb): ");
	for (i = 0; i < 71; i++)
		for (j = 1; j < 40; j++)
			if (j & 0x7)
				copytest(j, i);
	for (i = BUFFER_INCREMENT * 8 - 71; i < BUFFER_INCREMENT * 8 + 71; i++)
		for (j = 1; j < 40; j++)
			if (j & 0x7)
				copytest(j, i);

	fprintf(stderr, "ok.      \n");


	/********** lazy, cut-n-paste retest with MSb packing ***********/

	/* Test read/write together */
	/* Later we test against pregenerated bitstreams */
	oggpackB_writeinit(&o);

	fprintf(stderr, "\nSmall preclipped packing (MSb): ");
	cliptestB(testbuffer1, test1size, 0, oneB, onesize);
	fprintf(stderr, "ok.");

	fprintf(stderr, "\nNull bit call (MSb): ");
	cliptestB(testbuffer3, test3size, 0, twoB, twosize);
	fprintf(stderr, "ok.");

	fprintf(stderr, "\nLarge preclipped packing (MSb): ");
	cliptestB(testbuffer2, test2size, 0, threeB, threesize);
	fprintf(stderr, "ok.");

	fprintf(stderr, "\n32 bit preclipped packing (MSb): ");
	oggpackB_reset(&o);
	for (i = 0; i < test2size; i++)
		oggpackB_write(&o, large[i], 32);
	buffer = oggpackB_get_buffer(&o);
	bytes = oggpackB_bytes(&o);
	oggpackB_readinit(&r, buffer, bytes);
	for (i = 0; i < test2size; i++) {
		if (oggpackB_look(&r, 32) == -1)report("out of data. failed!");
		if (oggpackB_look(&r, 32) != large[i]) {
			fprintf(stderr, "%ld != %ld (%lx!=%lx):", oggpackB_look(&r, 32), large[i],
				oggpackB_look(&r, 32), large[i]);
			report("read incorrect value!\n");
		}
		oggpackB_adv(&r, 32);
	}
	if (oggpackB_bytes(&r) != bytes)report("leftover bytes after read!\n");
	fprintf(stderr, "ok.");

	fprintf(stderr, "\nSmall unclipped packing (MSb): ");
	cliptestB(testbuffer1, test1size, 7, fourB, foursize);
	fprintf(stderr, "ok.");

	fprintf(stderr, "\nLarge unclipped packing (MSb): ");
	cliptestB(testbuffer2, test2size, 17, fiveB, fivesize);
	fprintf(stderr, "ok.");

	fprintf(stderr, "\nSingle bit unclipped packing (MSb): ");
	cliptestB(testbuffer3, test3size, 1, sixB, sixsize);
	fprintf(stderr, "ok.");

	fprintf(stderr, "\nTesting read past end (MSb): ");
	oggpackB_readinit(&r, (unsigned char *)"\0\0\0\0\0\0\0\0", 8);
	for (i = 0; i < 64; i++) {
		if (oggpackB_read(&r, 1) != 0) {
			fprintf(stderr, "failed; got -1 prematurely.\n");
			exit(1);
		}
	}
	if (oggpackB_look(&r, 1) != -1 ||
		oggpackB_read(&r, 1) != -1) {
		fprintf(stderr, "failed; read past end without -1.\n");
		exit(1);
	}
	oggpackB_readinit(&r, (unsigned char *)"\0\0\0\0\0\0\0\0", 8);
	if (oggpackB_read(&r, 30) != 0 || oggpackB_read(&r, 16) != 0) {
		fprintf(stderr, "failed 2; got -1 prematurely.\n");
		exit(1);
	}

	if (oggpackB_look(&r, 18) != 0 ||
		oggpackB_look(&r, 18) != 0) {
		fprintf(stderr, "failed 3; got -1 prematurely.\n");
		exit(1);
	}
	if (oggpackB_look(&r, 19) != -1 ||
		oggpackB_look(&r, 19) != -1) {
		fprintf(stderr, "failed; read past end without -1.\n");
		exit(1);
	}
	if (oggpackB_look(&r, 32) != -1 ||
		oggpackB_look(&r, 32) != -1) {
		fprintf(stderr, "failed; read past end without -1.\n");
		exit(1);
	}
	fprintf(stderr, "ok.");
	oggpackB_writeclear(&o);

	/* this is partly glassbox; we're mostly concerned about the allocation boundaries */

	fprintf(stderr, "\nTesting aligned writecopies (MSb): ");
	for (i = 0; i < 71; i++)
		for (j = 0; j < 5; j++)
			copytestB(j * 8, i);
	for (i = BUFFER_INCREMENT * 8 - 71; i < BUFFER_INCREMENT * 8 + 71; i++)
		for (j = 0; j < 5; j++)
			copytestB(j * 8, i);
	fprintf(stderr, "ok.      ");

	fprintf(stderr, "\nTesting unaligned writecopies (MSb): ");
	for (i = 0; i < 71; i++)
		for (j = 1; j < 40; j++)
			if (j & 0x7)
				copytestB(j, i);
	for (i = BUFFER_INCREMENT * 8 - 71; i < BUFFER_INCREMENT * 8 + 71; i++)
		for (j = 1; j < 40; j++)
			if (j & 0x7)
				copytestB(j, i);

	fprintf(stderr, "ok.      \n\n");

	return(0);
}
#endif  /* _V_SELFTEST */

#undef BUFFER_INCREMENT
